The present disclosure relates generally to the field of adjustable vehicle seat assemblies. More particularly, the present disclosure relates to the field of track systems or arrangements for use with adjustable vehicle seat assemblies.
Vehicle seat assemblies are typically provided with a track system that enables the position of the seat assembly within a motor vehicle to be adjusted in the forward and rearward direction. Such adjustment capability is desirable to enable vehicle operators of various sizes to be seated comfortably and safely within the motor vehicle. Such seat assemblies commonly include two track members (but may have more) that move relative to one another and a latching mechanism that releasably retains the track members (and therefore the seat assembly) in a locked position relative to one another until the latch mechanism is released. Once the latch mechanism is released, the track members can be moved relative to one another, which allows the occupant of the seat assembly to adjust the position of the seat assembly and to then reengage or release the latching mechanism to hold the seat in the new location.
Latch mechanisms typically retain the seat assembly in a particular position by inserting one or more pins through apertures and/or slots that are provided in or on the track members that make up the track system, which has the effect of locking the track members in position with respect to one another. To unlock the tracks and allow the occupant of a seat to adjust the position of the seat, the one or more pins are removed from the apertures and/or slots. The strength of the lock between the tracks is generally limited by the strength of the pins and the strength of the track that receives the pins.
The track members will have a limiting portion or area that serves as the limiting factor of the track with respect to its strength. For example, the limiting portion of many tracks is the area around the apertures that receive the pins. When the seat is subjected to a load, the pins tend to cause this area to deform or deflect. In order to meet certain strength requirements, manufacturers often use a track having a uniform wall thickness and choose the wall thickness based on what is needed to allow the limiting portion or area of the track to satisfy the strength requirements. Similarly, when adapting a particular track design for use in an application having a greater strength requirement, manufacturers often increase the thickness of the material used to form the track to the extent needed to allow the limiting portion or area of the track to satisfy the greater strength requirement.
Although increasing the thickness of the material used to form the track generally provides the track with the desired strength, the additional strength often comes at the expense of significant additional weight, a potentially larger cross-sectional area of the track, additional development, testing, and design, additional tooling, and additional cost. Moreover, the increased wall thickness may also require the use of different or redesigned components (e.g. a different size of ball bearings used between the sliding tracks, etc.) to account for the increased thickness of the track.
To provide a more reliable, more widely acceptable seat track system or arrangement that is adaptable to meet different strength requirements, which avoids one or more of the above-referenced and other problems would represent a significant advance in the art.